The invention relates to a method of forming a pouch for dispensing viscous material.
Viscous materials can include sealant, mastic, adhesive, glazing, caulk, grout and glue compositions. Typically, such viscous materials are packaged, stored or commercialized in cardboard containers or plastic dispensers or cartridges that are adapted to be loaded into an extrusion device such as a caulking gun. These viscous materials include silicone sealants and caulks that are used in building and construction applications. Some of these compositions are referred to as room temperature vulcanizable (RTV) compositions. They may include a moisture-curable polyorganosiloxane polymer, filler, and a condensation cure catalyst. When used as sealants, these compositions can be packaged in a moisture impervious tube and applied to a substrate by extrusion from the packaging tube.
There are difficulties associated with these containers. For example, some materials are merchandised in cartridges for loading into a caulk dispenser or gun. The dispenser or gun is another item that must be purchased, stored, cleaned and maintained as part of the caulking process. The dispenser or gun may be cumbersome and difficult to operate, especially in constrained spaces in buildings under construction. Also, the dispensing device may require significant hand strength, which adds challenge to dispensing and laying a clean sealant bead.
In one process, a quantity of sealant is expressed from a dispensing tube or cartridge directly to a crevice to seal the area when dried. Typically, the dispensing tube or cartridge will contain more material than an amount required for a particular sealing job. Usually some unused portion of the tube remains after a required amount has been dispensed. The dispensing tube with the unused portion is discarded or is saved for futures use. Discarding is uneconomical and may be highly undesirable for environmental reasons. At present, there is no known recycling available for the wide variety of sealant compositions available on the market.
If the container with residual sealant is not discarded, it will need to be capped to save the material without setting for future use. But, the sealant may include a volatile component that will evaporation to harden residual material. Other sealants may be settable from exposure to atmosphere oxygen. And unless the container is correctly reclosed, the residual material will be lost.
Some dispensing containers are merchandised with a nozzle-engaging, snap-fit bead and groove or screw thread to provide a secure fit to the container body. But these caps are fragile pieces that are easily split or otherwise damaged from over-tightening. Or, the snap-fit bead and groove may not provide an enduring reclose fit until the time when the tube is next required for a caulk job. Some informal capping devices have included the placing of a nail into the tube opening, to effect a plug type reclosure. Or, the container cap may be merchandised with a plug member to provide this function. But frequently, these solutions do not prevent content hardening for more than a short period of time.
Other reclosing approaches have included wrapping the container tip with aluminum foil or plastic wrap, securing with a rubber band and enclosing the entire container in a sealable plastic packet. But, oftentimes these mechanisms do not work because the packets rupture or the packets contain enough air to dry the tube contents. And, a foil or wrap can not be closely and tightly wrapped around the tube and nozzle without air gap.
There is a need for a viscous material container such as a small pouch that overcomes the problems of waste and difficulty of use of current dispensers. And. there is a need for a method to form such a pouch.